A recent report that a Chinese computer chip used by the U.S. military has a hidden backdoor that could allow the manufacturer to disable devices are overblown, one security researcher says.

Researchers at Cambridge University issued a dire warning today about a security bypass they said they had identified in a nonencrypted chip made by Microsemi in China, and used in weapons, nuclear power plants, and even public transportation.

"We scanned the silicon chip in an affordable time and found a previously unknown backdoor inserted by the manufacturer," security researcher Sergei Skorobogatov wrote in the publication of his findings. "This backdoor has a key, which we were able to extract. If you use this key, you can disable the chip or reprogram it at will, even if locked by the user with their own key," he wrote.

"In other words, this backdoor access could be turned into an advanced Stuxnet weapon to attack potentially millions of systems," he continued. "The scale and range of possible attacks has huge implications for [U.S.] national security and public infrastructure."

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The Cambridge report comes out as security researchers announced the discovery of a Stuxnet-like targeted virus stealing sensitive information from Windows-based computers in the Middle East. While Stuxnet targeted the controls of an Iranian nuclear facility, the new malware -- dubbed Flame -- appears designed to steal information about targeted systems and stored files, as well as computer display contents and audio conversations.

However, the report of threats posed by the backdoor found in the field-programmable gate array chip are "bogus," according to another security researcher. "While they did find a backdoor in a popular FPGA chip, there is no evidence the Chinese put it there, or even that it was intentionally malicious," writes Robert David Graham at Errata Security. "Backdoors are common but rarely malicious."

While acknowledging the existence of the backdoor, Graham pointed out that the researchers offered no evidence of its source. He also said he doubted there was anything malicious behind it and called the military security threat angle "really distant."

"The Chinese might subvert FPGAs so that they could later steal intellectual property written to the chips, but the idea they went through all this to attack the U.S. military is pretty fanciful," he concluded.